according to an fbi bomb technician, he mixed and created the explosive chemicals himself, including explosive powders and live ammunition, and homemade napalm. he saturated his carpet in gasoline and oil and rigged an elaborate system of containers to explode. >> you're talking about that he rigged that elaborate system to explode. the way he did that was really bizarre and when i saw kind of what he did and what he thought might happen, i don't know, it gave a sense of how deviant his mind is. can you tell everyone about that? >> reporter: absolutely. remember, all of this, he had hoped, would have gone off before he started shooting in the theater to distract first responders, take them to his apartment and then several miles away, he would be entering the movie theater. there were a couple ways to trigger these explosive devices, the ieds. one would have been by opening the door which would hit a trip wire and cause chemicals to mix, exploding on to the floor and causing the entire apartment to explode. another one which was i thought stunning, we had not heard this, was that the